Usually drugs and liquids are delivered to patients through a catheter or intravenously in a peripheral blood vessel. This method is satisfactory in cases where the blood pressure of the patient is at normal levels. However, when blood pressure drops, for example, during a heart attack, drug overdose, or severe hemorrhaging, the peripheral blood vessels collapse and access to these vessels is difficult or impossible. In such cases, an alternative to intravenous infusion is intraosseous infusion. An intraosseous infusion apparatus may be used to infuse drugs and other liquids into the bone marrow under such emergency conditions. In particular, an intraosseous device is used to penetrate the patient's skin, the subcutaneous layer between the skin and the top of the cortical layer of the bone, the cortical layer of the bone, and the bone marrow, and to supply drugs or fluids directly to the blood supply system of the bone. Typically, the sternum, femur, tibia or other bone near the skin is used. Intraosseous infusion can also be used on patients with blood vessels that are hard to find and on young children whose blood vessels are small and also hard to find. Intraosseous infusion can also be used in emergency or battlefield conditions where quick intravascular access may make the difference between life and death. The caregivers in these situations have low levels of training and need an intraosseous device that is simple and rapid to use.
Although intraosseous infusion is a feasible alternative to intravascular infusion, it has not met with widespread acceptance and popularity for a variety of reasons. One reason for this is the practical difficulty in inserting the infusion needle to the proper depth in the bone in order to access the marrow. One method to overcome this problem has been to use a stop or marker on the needle to indicate when the needle has penetrated to a particular depth. This method has not been effective since it requires an estimation of the required depth and careful control during advancement of the needle. Skin and tissue thickness overlying the bone range from 3 mm to 30 mm and thus the skin surface cannot be used as a reliable reference point. A trained individual like a doctor would be needed to determine the correct depth and insert the intraosseous device. This can be difficult even for highly skilled professionals. Another method to overcome this problem has been to monitor the resistance to the penetration of the infusion needle. The resistance is high when the needle goes through the cortical layer of the bone but decreases when it hits the bone marrow. This method is not very effective since resistances may vary. Again, a highly trained individual is required to advance the intraosseous needle or tube slowly and feel for the changes in resistance.
Intraosseous penetration of the cortical layer of the bone to the bone marrow is also needed when a sample of bone marrow from a patient must be taken. Again a needle or tube must be inserted through the subcutaneous layer into the bone so that the bone marrow can then be aspirated. Again, only a highly trained individual can accurately determine the depth of the penetration of the tube or needle into the bone marrow.
In U.K. Pat. No. 1,315,796, issued to Pashenichny et al., a device for intraosseous injection is disclosed consisting of an outer tube with a screw and a male thread on one end and an inner tube fitted into the outer tube. The device is drilled into the osseous tissue, the inner tube is removed and a cannula is connected to the outer tube. U.S. Pat. No. 4,969,870, issued to Kramer et al., discloses an apparatus for intraosseous infusions having a base positioned with its lower surface against the patient's skin and the infusion tube is pushed through the skin and then rotated to thread through the bone until continued rotation of the tube no longer advances the tube. In both of these devices, there is no automatic depth sensing mechanism. In U.S. Pat. No. 3,815,605, issued to Schmidt et al., an intraosseous device has pins or legs similar to a bone probe that penetrates through the subcutaneous layer. The user releases a compressed spring that exerts a force on and delivers energy to a striker pin to cause it to penetrate the bone. A striker-pin holder that couples the spring to the striker pin engages a shoulder, which houses the bone probe, thereby limiting the penetration of the striker pin into the bone. Once the spring is released there is no user control over force applied to the striker pin. Thus, if the spring force is insufficient to penetrate the bone cortical the device becomes inoperative. Although this device does have a bone probe which allows the bone cortical layer to be used as a reference point in determining the depth of the penetration of the striker pin instead of the skin, there is no automatic release mechanism to prevent over-penetration of the bone marrow by the coupling member. When the striker-pin holder engages the shoulder, the excess energy released from the spring may drive the coupling member downwardly and over-penetrate the bone.
U.S. Pat. No. 5,520,650 issued to Zadini discloses a device for inserting a cannula into a body cavity. A piston is pushed by hand so that an attached cannula penetrates the skin. Once well under the skin the operator releases the piston and the piston is urged to return by a spring bias creating a vacuum in the piston chamber. The vacuum draws body fluid into the cannula and piston chamber until the vacuum drops. With the vacuum low enough, the piston moves back against an arrest pin releasing an interface member to be urged forward by a spring causing an arrest rod to be locked which, in turn blocks further movement of the catheter or needle. Zadini requires a hollow cannula be inserted since it senses pressure in order to hold the cannula from causing the chain of events that locks an arrest rod and prevents further insertion of the hollow cannula. The needle tip is expected to encounter a fluid which will flow into the needle, destroying the vacuum in the chamber and allow the piston to move, thus triggering the arrest mechanisms of the device. Zadini also requires that the overlying tissue have sealing qualities. Thirdly, Zadini arrests movement of the cannula immediately upon entry into a suitable body cavity and does not detect relative position within a target cavity, but merely whether the cannula is in the cavity or not.
U.S. Pat. No. 4,874,380 issued to Hesketh discloses a releasable catheter retaining device mounted on a patch which has a post to which is anchored a cable tie. The cable tie is used to engage a catheter. The sole function of the patch is to retain a catheter.
Battenfield discloses a template for instructing proper insertion of a means for draining a distended bursa. The template is for use on either a right or left knee and has locating indicia marked on it for visual alignment with the patella and tibia. Since visual alignment alone is unreliable it would be desirable to combine such a method with a more mechanical method of alignment.
Other similar apparatus for intravascular infusion (U.S. Pat. No. 5,527,290 issued to Zadini et al. and U.S. Pat. No. 5,480,388 issued to Zadini et al.) and tracheotomies (U.S. Pat. No. 4,556,059 issued to Adamson, Jr.) may have automatic trigger mechanisms that use a spring for self-propelled insertion. None of the prior art discloses a release mechanism that controls the depth of penetration of the penetrating means inserted at arbitrary speed through arbitrary thickness of overlying tissue, against an unknown resistance.
Another problem in employing intraosseous infusion is the need for quickly and easily finding the proper location on a patient's body for insertion of the infusion tube. A semi-skilled caregiver in an emergency situation would not be able to quickly identify the target location for intraosseous infusion. Prior art discloses templates for guiding the insertion of syringes for draining the bursa of the knee and for insertion of spinal marker needles. A template for guiding a caregiver to the correct location for draining the bursa of the knee along with the hypodermic needle used in the process is disclosed in U.S. Pat. No. 5,364,361, issued to Battenfield. U.S. Pat. No. 4,985,019, issued to Michelson, teaches an X-ray marker disc with a grid pattern and indicia for determining the location and orientation of the spinal marker needle. There is a need for a template to guide the placement of an intraosseous infusion apparatus so that a semi-skilled caregiver can accurately and very quickly determine the site of intraosseous infusion.
A third problem with intraosseous infusion is that strain and stress on the infusion tube that protrudes above the skin may cause dislodgment of the tube from the bone, tearing of the skin or overpenetration of the infusion tube. One cause of such stress is the movement of skin and tissue which may cause strain on the infusion tube and may dislodge it. The infusion tube may be placed under tension by the intravenous fluid supply tube. Forces or pressures from objects pressing on the intraosseous infusion site may push the infusion tube too far into or through the bone. This problem is particularly difficult when a patient is being transported in an ambulance or in a war zone where movement of the patient under uncontrolled conditions is required.
Prior art discloses several devices for supporting catheter tubing, for example U.S. Pat. No. 4,397,641, issued to Jacobs, which teaches a catheter support member and U.S. Pat. No. 5,456,671, issued to Bierman, which teaches a catheter anchoring system. Prior art also discloses several protective coverings for the catheter infusion sites as in U.S. Pat. No. 5,074,847, issued to Greenwell et. al., which discloses a shielding device and a method for holding a heparin lock secured to a catheter and U.S. Pat. No. 5,449,349, issued to Sallee et al., which discloses an intravenous tubing cover/protector. These supports are customized for catheters. Thus, a need for an intraosseous tube support which can create a protective loop of slack, and a protector covering the intraosseous infusion site and intraosseous infusion tube exists.
It should therefore be appreciated that there is a significant need for an intraosseous infusion or aspiration apparatus and a related method that can be used quickly and easily by even low-skilled caregivers in emergency or field conditions. Further there is needed such a device that provides for quick positioning of the target area and one that enables semi-skilled users to reliably and accurately position an intraosseous infusion device. There is also a need for such a device that provides relief from the stress and strain placed on the tubing and protection against dislodgment or over-penetration.